Student Projects - Purdue University...• Imaging processing and programming in matlab....

Student Projects

Projects

• Measuring and calculating the radiation dose for animal undergone CT. This could be abdominal, thorax, skull, or whole body CT (Dr. Heng; Dr. Stantz)

• Investigate feet and ankle dose from fluoro, perform dosimeter comparisons for certain procedures, and look at better dosimetry for lens of the eye (Dr. Harris and RSO at IUSM).

Projects, Cont’d

• Implementing 3D US Treatment Planning in dog patients• Goal: To develop and test an onboard 3D Ultrasound imaging method to treat

Bladder Cancer in Dog Patients using IMRT• Experience: IMRT treatment planning; CT imaging; US imaging• Dr. Stantz and Dr. Plantenga

Dr. Stantz

• Imaging Hypoxia• Using DCE CT imaging to imaging intra-tumor necrosis

• Goal: To analyze Clinical CT data to identify the location of necrotic foci within solid tumors• Background: the formation of avascular necrotic regions within a tumor is correlated with

poor patient outcome. Characterizing these regions using DCE-CT and targeting these regions with hypofractional doses of radiation is our objective.

• Experience: DCE CT imaging and analysis; advanced biophysical models of imaging; Integration into treatment planning software

• Analysis of normal tissue physiology undergoing therapy • Goal: To analyze changes in tissue/organ physiology prior-to, during, and after therapy• Background: The effects of non targeted tissue is relatively unexplored and can significantly

impact patient outcome. • Experience: DCE CT imaging and analysis; advanced biophysical models of imaging; treatment

planning software

• Implement DCE-MRI using the Life Sciences MRI

Dr. Stantz, Cont’d

• Help develop RACT scanner• Objective: Support in the development of a new scanner modality which will

be tested at a clinical proton therapy facility

• Apply Deep learning algorithms in Medical Imaging

Nie Lab• Development of non-invasive neutron activation analysis

(NAA) technology to quantify metals in human tissue in vivo

• Development of non-invasive x-ray fluorescence (XRF) technology to quantify metals in human tissue in vivo

• Development of associated partial neutron imaging (APNI) technology for elemental analysis in medical diagnostics

• Development of neutron boron capture therapy technology for disease treatment

• Development of synchrotron XRF technology for elemental mapping in biological samples

• MC simulations

Improve HDR prostate brachytherapy delivery

accuracy Yi Le Ph.D

Associate Professor IU School of Medicine

Radiation Oncologyyile@iu.edu

Real Time Ultrasound Base HDR brachytherpyfor prostate cancer

• Pros:• Implant and treat at same time• Better soft tissue visualization

• Cons:• Uncertainty in catheter

reconstruction

projects

1. estimation of delivery uncertainty due to catheter reconstruction error 2. better template design to reduce catheter blocking (3D printing)3. better imaging processing to improve catheter reconstruction4. automatic catheter reconstruction

Educational goals

• Learn process of HDR prostate brachytherapy• Learn HDR prostate brachy planning software• Learn Ultrasound imaging• Imaging processing and programming in matlab

Lymphocyte-sparing Effect Of Radiotherapy In Patients With Pelvic Irradiation

Introduction:•The immune system plays an important role in cancer suppression and determines cancer prognosis.

•Radiation damage can lead to apoptosis of circulating lymphocytes and lessens the antitumor effect of the immune response.

•Lymphoid organs are critical components of the immune systems, changes in the function of the lymphoid organs significantly affects the lymphocyte counts.

•The severity of the radiation-induced lymphopenia varies depending on the radiation dose received by the lymphoid organs in the treatment sites.

Sook Kein Ng Ph.D. Assistant Professor sookng@iu.edu Objective:• To investigate the correlation between the decrease in lymphocytes during

radiotherapy and the irradiation dose to the lymphoid organs in patients with colorectal cancer.

Methods and materials:•Each organ in the pelvic area will be contoured and its corresponding dosimetry calculated in treatment planning system.

•Blood samples will be obtained before, during and after radiotherapy.

•Changes in the lymphocyte counts between baseline values at pre-radiotherapy and during or after radiotherapy will be evaluated to determine dose-response correlation between lymphoid organs dose and lower lymphocyte counts.

•Identify dose constraints for patients undergoing pelvic irradiation base on the finding.

Education Topics :• This project allows student to learn human anatomy, treatment planning

techniques, radiobiology and radiation safety that will be vital to serve as a medical physicist.

Small research projectsColleen DesRosiers Ph.D. cmdesros@iupui.edu

Associate Professor IU School of Medicine

Purdue University Medical Physics Graduate Program3/30/18

Proposal #1

Objective: Evaluating the dosimetric differences between a CT planning scan image generated with 12 bit versus 16 bit processorBackground:Radiation dose distributions are dependent on electron density of the medium irradiated. In a treatment planning system (TPS) the electron density is calculated based on HU to electron density conversion table. The HU scale depends on the processing; specifically, a 16 bit reconstructed image will have a broader HU range than a 12 bit, which may impact the resulting dose distribution.

Proposal #1 (cont)Experiment:1. A clinical CT scan will be performed on an electron

density phantom. The image will be reconstructed with 12 bits and 16 bits.

2. Both scans will be imported into the TPS and dose distributions from an identical treatment plan will be generated using the HU/electron density conversion table for 12 bits.

3. DVHs and point doses will be compared between the two image sets.

4. A HU/electron density conversion table will be created for 16 bits and dose calculations will be generated and compared with calculations performed using the 12 bit scale.

Proposal #2

Objective: To standardize the block transmission factors for lung blocks in the TBI setting, based on patient/block geometry.Background: Attenuation coefficients are based on transmission measurements made in good geometry (narrow fields, large distance). For total body irradiation (TBI), 50% transmission blocks are used to shield the lungs to be less than 900 cGy to reduce the risk of radiation pneumonitis. However, determining the appropriate thickness of the blocks to produce the desired dose will depend on the size of the blocks, which can vary from about 20 cm2 to 100 cm2, depending upon the age/size of the patient.

Proposal #2 (cont)

Experiment:1. Three sizes of blocks will be cut to at least three different thickness

(total number of blocks = 9) and transmission measurements will be made in the TBI setting.

2. Dose calculations will be performed based on typical patient geometry (lung/patient sizes) for infants, children/small adults, and adults

3. A spreadsheet will be designed to calculate the optimum thickness of the blocks to deliver the desired dose to the lungs, based on the lung size and patient geometry.

Two Clinical Research Projects

Colin Huang, PhD, Assistant Professor/Medical Physicist,

Radiation Oncology, IU School of Medicine

• Goal: 1. To quantify the angular dependence of the response from an ArcCheck QA device when the incident beams are not at oblique angles. 2. How does this affect the IMRT/VMAT Arc QA results.

I. Angular dependence of the response for ArcCheck QA device

• Learn to operate the linear accelerator, including setting collimator, gantry, and couch angles; setting field size beam energy, MUs and beam on. (under supervision)

• Become an expert of using the ArchCheck QA software and device to do measurements and perform analysis.

What can you get from this project

• Learn to create IMRT/VMAT Arc QA plans from original plan

• Learn to deliver a IMRT/VMAT Arc QA plan and use ArcCheck to analyze the QA results.

• Write a conference abstract

What can you get from this project

• Background: Stereotactic body radiation therapy (SBRT) has been

used for treatment of spinal cord compression. However, the treatment usually starts at least 1-2 days

after simulation due to complicated planning and QA procedures.

II. Dosimetric comparison on two different plan approaches for emergency spine SBRT patient

Traditionally, the patient will get a APPA plan for the first fraction and then the SBRT for the following fractions.We studied the feasibility of using a pre-QAed

universal SBRT plan for the first fraction of a 5-fraction regimen in emergency spine cases.

Background

• Goal: To compare the dose to the PTV target and OARs from the tradition approach (1 fx APPA + 4 fx SBRTs) and the new approach (1 fx universal SBRT + 4 fx SBRTs, these have been done).

Goal

• Learn to use Eclipse treatment planning system.• Learn to create APPA plans for spine patients.• Learn to run SBRT inverse planning optimization using preset

optimization criteria, using a base plan.• Learn to collect dose from DVHs generated.• Submit a conference abstract.

What can you get in this project

My contact: colhuang@iu.eduColin Huang, PhD, Assistant Professor/Medical Physicist